Your body uses inflammation to protect you from invading germs and to heal injuries. When a germ gets into your body, you make cells and proteins to kill that germ. As soon as the germ is gone, your immunity is supposed to dampen down and stop making large amounts of these cells and antibodies. If your immunity does not stop making excessive amounts of cells and proteins to kill germs, these same cells and proteins can attack you to cause "auto-immune" diseases such as rheumatoid arthritis and increase your risk for heart attacks, cancers, strokes, diabetes and many other diseases.

How Your Immunity Protects You
You have no germs before you are born, but soon after birth, bacteria start to grow everywhere on your skin surface, in your respiratory tract and in your entire digestive tract. Most of these germs are good for you and help in many different ways. They help you to digest and absorb nutrients from the food that you eat, and to eliminate waste products. They colonize the linings of your respiratory tract and intestines to help keep harmful germs from growing there.

However, germs are not supposed to get into your bloodstream. When germs invade your bloodstream through breaks in your skin, intestinal tract or respiratory tract, your immunity recognizes that the germs' proteins are different from the proteins on your own cells. Your immunity produces proteins called antibodies that attach to and try to kill the invading bacteria or virus, cells that literally eat the invading germs, and cytokines that marshal your entire immune system to destroy germs that are trying to invade your body.

Your Immunity Helps to Heal Damaged Tissue
When you cut your skin, pull a muscle, break a bone or damage any part of your body, your immunity produces large amounts of the same cells and proteins that you use to kill germs, to start the healing process. Anything that slows down your immune system also delays healing. While your injury is healing, you will notice the symptoms of your immunity in action: swelling, heat and pain. This is called inflammation.

Your Immunity Makes You a Better Athlete
You cannot make a muscle stronger unless you exercise so vigorously that you damage that muscle. If you want to become stronger, you have to exercise intensely enough to have sore muscles on the day after an intense workout. Then your immunity brings in the same cells and proteins that it uses to kill bacteria and viruses and these cells and proteins heal the damaged muscles. When muscles heal, they become bigger and stronger.

Your Immunity Helps to Prevent Cancer
Each day, your body makes new cells to replace worn out and damaged cells. Normal cells live a certain number of days and then die. For example, normal red blood cells live 120 days and die. Normal skin cells live 28 days and die. Normal cells lining your inner lips live 24 to 48 hours and then die. Cancer means that a cell does not die and tries to live forever. For example, breast cancer does not kill when it stays in the breast, but breast cancer cells can become so numerous that they leave the breast and can kill you by travelling to and destroying your brain, your liver, your bones or any other vital organ. Each day your body make millions of cancer cells, but your immunity recognizes that cancer cells are different from your cells and kills them the same way it kills germs. You develop cancer only when the cancer cells are allowed to multiply in your body, and cancer spreads when your immune system fails to recognize that the spreading cancer cells are different from your normal cells.

When Your Immunity Stays Active Too Long, It Attacks Healthy Tissue
While you are fighting a cold or the flu or healing from an injury, you can expect to see signs of your immunity in action, such as a fever, swelling and pain. When the job is done, these symptoms are supposed to go away. Chronic inflammation means that your immunity does not stop working, even though there are no germs that need fighting or injuries that need to be healed. Your immunity stays active and uses the same cells and proteins that kill germs to attack and damage your own cells. Chronic inflammation can lead to:

• Heart attacks: The same immune chemicals that dissolve the outer membranes of bacteria can dissolve the inner linings of your arteries to punch holes in them and start the formation of plaques. A heart attack occurs when a plaque breaks off from the inner lining of an artery leading to your heart, travels down an ever-narrowing artery, and prevents blood from reaching parts of your heart muscle. If you do not die during a heart attack, the part of your heart muscle deprived of oxygen dies and is replaced by scar tissue.

• Strokes: A stroke can occur when plaque breaks off from an artery leading to your brain.

• Diabetes: One type of diabetes can occur when your immunity attacks and kills the beta cells of the pancreas that produce insulin. You develop diabetes because you lack insulin. Another type of diabetes can occur when your overactive immunity prevents your cells from responding to insulin, causing very high rises in blood sugar and insulin levels.

• Cancers: An overactive immunity can attack cells to damage the genetic material called DNA. The abnormal DNA that results can turn normal cells into cancerous ones.

• Auto-immune Diseases: Specific diseases that appear to be caused by an overactive immunity are grouped together and called auto-immune diseases. Your overactive immunity can cause rheumatoid arthritis to destroy your joints and tendons, lupus to destroy your kidneys and other parts of your body, or other diseases such as dermatomyositis and scleroderma.

Other sources of chronic inflammation include:
• exposure to X rays and other radiation,
• exposure to harmful chemicals such as certain insecticides, herbicides and industrial chemicals,
• a chronic infection anywhere in the body.

More Reasons to Live Healthfully
I believe that everyone should try to develop healthful habits. A healthful lifestyle can help you avoid many diseases and if you already have a disease, a healthful lifestyle can help you fight that disease and prolong your life. You may correct a faulty habit and still develop a related disease years later. For example, if you stop smoking, you are still at risk for smoking-related cancers for the rest of your life, but one year after you stop smoking, your risk for a heart attack is no greater than that of a non-smoker. The same lifestyle factors that increase your risk for heart attacks also increase risk for strokes, dementia, diabetes and many other diseases. Any scientific breakthrough that helps to prevent heart attacks will probably help to prevent other diseases also.

About the Author: Gabe Mirkin, MD

Sports medicine doctor, fitness guru and long-time radio host Gabe Mirkin, M.D., brings you news and tips for your healthful lifestyle. A practicing physician for more than 50 years and a radio talk show host for 25 years, Dr. Mirkin is a graduate of Harvard University and Baylor University College of Medicine. He is board-certified in four specialties: Sports Medicine, Allergy and Immunology, Pediatrics and Pediatric Immunology. The Dr. Mirkin Show, his call-in show on fitness and health, was syndicated in more than 120 cities.
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